At present, influences of human daily lives themselves onto environments have raised problems in every field. One of the problems is generation of pollutants caused by incineration of garbage.
For example, an exhaust gas exhausted from municipal waste incinerators contains soot/dust, hydrogen chloride (HCl), SOx, NOx, heavy metals including mercury, or minor constituents such as dioxin, and it is necessary to remove these toxic substances from a viewpoint of environmental protection. Above all, with respect to dioxins (generic term of polychlorinated dibenzo oxine: PCDD and polychlorinated dibenzo furan: PCDF), it has been reported that dioxins are remarkably strong in toxicity and further have carcinogen, and trapping/collecting/removing of dioxins has been taken up as an urgent problem.
However, when the exhaust gas from the incinerator is treated, dioxins cannot be reduced to a desired low concentration in some case.
That is, dioxins generated in a incineration process of garbage are substantially decomposed in a secondary combustion chamber, but the temperature of the incinerator exhaust gas needs to be lowered to a low temperature suitable for dust collection from a high temperature at about 350 to 900° C. in exhaust gas treatment processes such as a heat recovery process, cooling reaction process, and dust collection process. In this case, from a viewpoint of prevention of recomposition of dioxin, it is necessary to quench/pass the gas through a de novo resynthesis temperature region of dioxin (in the vicinity of about 300° C.) in a short time.
When the de novo resynthesis temperature region (300° C.) of dioxin is rapidly cooled to lower the temperature at 150° C. or less, a device is enlarged in gas cooling of a conventional heat exchanger type, and this has been inefficient.
Therefore, vaporization latent heat has been used to perform the cooling by water spray, but a large volume is required, and this has a problem that equipment of the device is also enlarged in size and much running cost is required.
Additionally, a so-called honeycomb structural body is a structural body in which a plurality of cell arrays constituted of a large number of juxtaposed cells are formed. When a ceramic porous body including micro fine pores is used as a base material in addition to a structural material light in weight and high in strength (for an airplane, and the like), a catalyst carrier having a large ventilation volume (for purifying an automobile exhaust gas), and the like, the structural body is also used as a dust collecting filter having a filter area per unit area, or a solid-liquid separation filter. Furthermore, application to a cooling device, extracting device, humidity adjusting device, and the like has also been studied. However, concrete proposals for these devices cannot be said to be complete in practicality in actual situations.
The present invention has been developed in consideration of the problems possessed by the related art, and an object of the present invention is to provide a liquid-to-gas contact device which allows liquid to permeate a plurality of partition walls from an outer peripheral surface side of a honeycomb structural body by a capillarity phenomenon and which uses vaporization latent heat generated at the time of contact of a gas with the liquid and which can accordingly be superior in thermal efficiency, simple, and compact.